Test for the suitability of thickener in the print paste formulation and other conceptTest

8/10/2019 Test for the suitability of thickener in the print paste formulation and other conceptTest

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Test for thesuitability of

thickener in the printpaste formulation

and other concept.


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PRINTING Process of applying colour to fabric in definitepattern or design .

Styles of printing

Direct print coloration Discharge style Resist style Special styles
http://en.wikipedia.org/wiki/Image:Morris_Evenlode_textile_drawing.jpg


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Methods of printing

Block printing Screen printing Digital printing

Roller printingTransfer printing


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Textile Printing Process Fabric Preparation Flat Screen/Rotary Screen/Roller Preparation

Print paste Preparation Printing on fabric

Drying

Fixing Washing and Soaping

Final Drying


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THI KENERSHigh molecular weight substances.

Impart stickiness and plasticity to thepaste.

Hold the dye particle in the desired placeon the fabric.


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TYPES OF THICKENERSStarchBritish gum

Guar gum AlginateIndalca gumGum Tragacanth


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printing sequenceReactive printing

Print paste

Printing

Drying

Fixation

Washing off


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PRINT PASTE FORMULATIONReactive Dye on cotton:-

Dyes form covalent bond with cellulosic fibers.These dyes can be brighter & faster-diffusing.


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Thickeners Alginates are the only natural thickener suitable for use inprinting with reactive dyes.

All other carbohydrates react with dye & this results in lowcolour yield or unsatisfactory handle(due to insolublisationof thickener).Recipe for 1000 g paste:

alginate thickener - 400-500 g

urea - 100-200 gsodium bicarbonate 20 gsod. m- nitrobenzenesulphonate -10 g

water -470-270 g


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Synthetic thickener with anionic charges can also be usedfor reactive dyes ( because of great colour yield and lesscost).

Recipe for 1000 g paste: F or half emulsionemulsifier - 10-20 g water - 280-90 gurea - 80-150 gsod. Bicarbonate - 20 gsod. m- nitrobenzenesulphonate -10 galginate thickener - 100-200 g white spirit - 500 g


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Reactive dyes in textile printingInfluence on the print paste stability

6

78

9

10

1112

13

14

Remazol Salt FD

sodium acetatesodium bicarbonate

sodium carbonate

sodium silicate

caustic soda solution

alkalipH-value Reactive dyes do hydrolyze

* alkali

*temperature

by increasing the pH-value each step

by 8 10 times faster

at rising temperature per 10 C

3 5 times faster


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Drying: at 100-120 C

Fixation :It is most important process in printing of textiles.In fixation, steaming of fabric is done.Steaming at 130-160 degree celsius for 30-60 sec.

Urea used in the printing process hold some amount of water with it, which is required for fixation of print on thefabric.In the absence of urea colour yeild is low.


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Washing off:o First rinse the fabric with cold water(surface dye &

auxilaries must be removed).o High temp(at boil) washing is done to remove

hydrolysed dye from inside the fibres.o Then a cold rinse completes the washing process.


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Precautions in printing paste

Urea amountThickener a lg inate /synthet icType of pr int Amount of pas teDye


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Reasons For Development ofsynthetic thickener

Diminishing supply of natural thickeners.Increasing cost of natural thickeners.

Less purityPoor thermal stabilityInadequate flow propertiesIn pigment printing kerosene is used as emulsionthickener which led to problems like pollutionregulation, fire hazards and shortage of kerosene.


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Synthetic thickener for Reactive dyes

Gum synth TRR is used for reactive dyes.It is an acrylic based thickener.It increases the brightness of print. Wide ph range (2-11).Sharper outlines.Reduction of urea,upto 50%.

h h k f


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Synthetic thickeners forDisperse dyes on PET

Indalca gum is the natural thickener used forpolyester.It had disadvantage that it does not easily removedduring normal washing.So, to avoid this problem , a new thickener Gum synthTRD is developed.

It is used in conjunction with indalca to get themaximum desired result.


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Synthetic thickeners for pigment

printing Water/kerosene emulsion thickener were mainly used.Due to ongoing oil crises ,it is being replaced by Gum

synth TRPthickener.

It is acrylic based thickener.It is available in powder form.It gives higher depth of shades as compared toemulsion thickener.It gives good wash and rubbing fastness.


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Documents

Test for the suitability of thickener in the print paste formulation and other conceptTest